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Wonderful!
Rude for me maybe, but any ideas about the low pass filter? It seems no such
option in SPM2, but may I achieve low pass using some SPM function?


On 10/24/07, Torben Ellegaard Lund <[log in to unmask]> wrote:
>
>  Hi Maartje
>
>
> That is indeed possible, though a bit complicated. You get the matrix with
> the cosines via the program spm_filter. If you use the matrix in K.X0 as a
> user specified regressor, and turn off the normal HP filter by entering inf
> as the period, you can even make an F-test to se where the filter had an
> effect.
>
> Hope this helps
> Torben
>
>
>
>
>
>
> Torben Ellegaard Lund
> Assistant Professor, PhD
> The Danish National Research Foundation's Center for Functionally
> Integrative Neuroscience (CFIN)
> Aarhus University
> Aarhus University Hospital
> Building 30
> Noerrebrogade
> 8000 Aarhus C
> Denmark
> Phone: +4589494380
> Fax: +4589494400
> http://www.cfin.au.dk
> [log in to unmask]
>
>
>
>
>  >> help spm_filter
>   Removes low frequency confounds X0
>   FORMAT [Y] = spm_filter(K,Y)
>   FORMAT [K] = spm_filter(K)
>
>   K           - filter matrix or:
>   K(s)        - struct array containing partition-specific specifications
>
>   K(s).RT     - observation interval in seconds
>   K(s).row    - row of Y constituting block/partition s
>   K(s).HParam - cut-off period in seconds
>
>   K(s).X0     - low frequencies to be removed (DCT)
>
>   Y           - data matrix
>
>   K           - filter structure
>   Y           - filtered data
>
>  ___________________________________________________________________________
>
>   spm_filter implements high-pass filtering in an efficient way by
>   using the residual forming matrix of X0 - low frequency confounds
>  .spm_filter also configures the filter structure in accord with the
>   specification fields if called with one argument
>
>  ___________________________________________________________________________
>   Copyright (C) 2005 Wellcome Department of Imaging Neuroscience
>
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>  On 24/10/2007, at 13.19, Luijten, M. wrote:
>
>  Hi all,
>
> I am wondering whether and how you can visualize the cosines added by SPM
> when you enter a high pass filter. Is it possible to actually see what spm
> did?
>
> Thanks,
> Maartje
>
>
>


-- 
何宏建, He Hongjian
BioX laboratory of physics department, Zhejiang University.
Zheda Road 38, Hang Zhou, China.
310027
Phone: 86-571-87952811